package top.javahai.chatroom.config;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

/**
 * @author Hai
 * @date 2020/6/16 - 17:24
 * 生成验证码的工具类
 */
public class VerificationCode {

  private int width = 100;// 生成验证码图片的宽度
  private int height = 30;// 生成验证码图片的高度
  private String[] fontNames = { "宋体", "楷体", "隶书", "微软雅黑" };
  private Color bgColor = new Color(255, 255, 255);// 定义验证码图片的背景颜色为白色
  private Random random = new Random();
  private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
  private String text;// 记录随机字符串

  /**
   * 获取一个随意颜色
   *
   * @return
   */
  private Color randomColor() {
    int red = random.nextInt(150);
    int green = random.nextInt(150);
    int blue = random.nextInt(150);
    return new Color(red, green, blue);
  }

  /**
   * 获取一个随机字体
   *
   * @return
   */
  private Font randomFont() {
    String name = fontNames[random.nextInt(fontNames.length)];
    int style = random.nextInt(4);
    int size = random.nextInt(5) + 24;
    return new Font(name, style, size);
  }

  /**
   * 获取一个随机字符
   *
   * @return
   */
  private char randomChar() {
    return codes.charAt(random.nextInt(codes.length()));
  }

  /**
   * 创建一个空白的BufferedImage对象
   *
   * @return
   */
  private BufferedImage createImage() {
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics2D g2 = (Graphics2D) image.getGraphics();
    g2.setColor(bgColor);// 设置验证码图片的背景颜色
    g2.fillRect(0, 0, width, height);
    return image;
  }

  public BufferedImage getImage() {
    BufferedImage image = createImage();
    Graphics2D g2 = (Graphics2D) image.getGraphics();
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < 4; i++) {
      String s = randomChar() + "";
      sb.append(s);
      g2.setColor(randomColor());
      g2.setFont(randomFont());
      float x = i * width * 1.0f / 4;
      g2.drawString(s, x, height - 8);
    }
    this.text = sb.toString();
    drawLine(image);
    return image;
  }

  /**
   * 绘制干扰线
   *
   * @param image
   */
  private void drawLine(BufferedImage image) {
    Graphics2D g2 = (Graphics2D) image.getGraphics();
    int num = 5;
    for (int i = 0; i < num; i++) {
      int x1 = random.nextInt(width);
      int y1 = random.nextInt(height);
      int x2 = random.nextInt(width);
      int y2 = random.nextInt(height);
      g2.setColor(randomColor());
      g2.setStroke(new BasicStroke(1.5f));
      g2.drawLine(x1, y1, x2, y2);
    }
  }

  public String getText() {
    return text;
  }

  public static void output(BufferedImage image, OutputStream out) throws IOException {
    ImageIO.write(image, "JPEG", out);
  }
}
